28 lines
635 B
JavaScript
28 lines
635 B
JavaScript
'use strict';
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var numberIsNan = require('number-is-nan');
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module.exports = function (num) {
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if (typeof num !== 'number' || numberIsNan(num)) {
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throw new TypeError('Expected a number, got ' + typeof num);
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}
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var exponent;
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var unit;
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var neg = num < 0;
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var units = ['B', 'kB', 'MB', 'GB', 'TB', 'PB', 'EB', 'ZB', 'YB'];
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if (neg) {
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num = -num;
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}
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if (num < 1) {
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return (neg ? '-' : '') + num + ' B';
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}
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exponent = Math.min(Math.floor(Math.log(num) / Math.log(1000)), units.length - 1);
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num = Number((num / Math.pow(1000, exponent)).toFixed(2));
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unit = units[exponent];
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return (neg ? '-' : '') + num + ' ' + unit;
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};
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